Although three Japanese men currently own portions of the Bantamweight crown it's fair to say only one of them is seen as a real "champion" in one of the sports most packed division. That man is Shinsuke Yamanaka (20-0-2, 15), the destructive southpaw who once again defended his WBC world title against a highly regarded challenger, something that can hardly be said of his compatriots.Having claimed the WBC title back in November 2011 when he defeated Christian Esquivel via 11th round TKO Yamanaka has slowly become one of the divisions key men. Subsequent defenses against Vic Darchinyan, Tomas Rojas, Malcolm Tunacao and Jose Nieves have all furthered Yamanaka's reputation as a genuinely top tier fighter.Earlier today Yamanaka defended his world title for the fifth time as he took on tricky Mexican Alberto Guevara (18-2, 6) a man who went the distance with the then IBF Bantamweight champion Leo Santa Cruz, one of the most fearsome fighters in the sport today.The fight actually started well for Guevara who used his excellent footwork and speed to connect on Yamanaka and get out of range. Even on the ropes the Mexican was elusive and made Yamanaka struggle to connect. For those who had seen Guevara's fight with Santa Cruz this was expected because he had proven to be a very intelligent mover.Although Guevara was making life difficult for Yamanaka the Japanese fighter was being rewarded by the judges for being the man trying to make the fight and after 4 rounds the WBC's open scoring showed him leading on all three cards. It was perhaps controversial given the bright start from the challenger though it's the problem with being a light hitting "fancy Dan" taking on a hard hitting and popular fighter in their home country.After the competitive start by Guevara it was Yamanaka's turn to find his rhythm and that's what he began doing in round 5 as he gradually started to connect on the slowing Mexican. By the end of round 6 it was obvious that Yamanaka was turning this into his fight and his success were becoming more and more regular. It wasn't a beat down but it was starting to become one.Through round 7 the assault of Yamanaka became more and more evident and whilst Guevara was showing the same toughness he had against Santa Cruz it was starting to turn complete against him.If round 7 had been a bad one for Guevara round 8 was a total nightmare with the Mexican being dropped within the first 30 seconds. Now Yamanaka was on a seek-and-destroy mission and Guevara was doing all he could to survive, holding Yamanaka and back peddling through out. The Latino fire of Guevara was quickly being extinguished despite his refusal to just lie down. Despite refusing to just lose Guevara was dropped a second time late in the round as Yamanaka tried to finish it it there and then.Guevara was sent out for round 9 though unfortunately for him so too was Yamanaka who dropped him early in the round. This time the Mexican stayed down and took the full count, knowing that this was a battle that he wasn't going to be able to turn around and in fact a battle that was just going to become more and more painful.Following the contest Yamanaka was interviewed and suggested that he wanted a big fight in the US at either his natural Bantamweight or even Super Bantamweight. We dare say that he would prefer an immediate match up with either Koki or Tomoki Kameda, the WBA and WBO champions though they are unlikely to happen.With Nonito Donaire stopping Vic Darchinyan on Saturday night, we'd love to begin the calls for Yamanaka v Donaire or Yamanaka v Guillermo Rigondeaux. Two fights that would pit hard punching skilled fighters against each other in what could potentially be a chess match with explosions.